Conventionally, a projection image pickup device has been proposed that can stably pick up images, with the influence of ambient light such as sunlight or streetlight reduced, by picking up images in synchronization with an own light emitting device (Patent Literature (PTL) 1).
PTL 1 proposes a technique for obtaining a noise-reduced measurement signal by finding a weighted average of signals obtained from an image pickup device in synchronization with pulsed light from a projection device.